Xanthan Sulfuric Acid: An Efficient Bio-Supported and Recyclable Solid Acid Catalyst for the Synthesis of 2-minothiazole-5-carboxylates and 2-aminoselenazole-5-carboxylates
作者:Bowroju S. Kuarm、Janganati V. Madhav、Bhargavi Rajitha
DOI:10.2174/157017811797249443
日期:2011.10.1
An efficient method has been developed for the synthesis of 2-amino thiazole and selenazole-5-carboxylates from β-ketoesters, thiourea or seleno urea and N-bromo succinamide by using Xanthansulfuricacid as a solidacidcatalyst. The reaction work-up is very simple and the catalyst can be easily separated from the reaction mixture and reused several times in subsequent reactions.
Aqueous-Phase One-Pot Synthesis of 2-Aminothiazole- or 2-Aminoselenazole-5-carboxylates from β-Keto Esters, Thiourea or Selenourea, and <i>N</i>-Bromo-succinimide under Supramolecular Catalysis
2-Amino-4-alkyl- and 2-amino-4-arylthiazole-5-carboxylates and their selenazole analogues were synthesized by α-halogenation of β-keto esters with N-bromosuccinimide, followed by cyclization with thiourea or selenourea, respectively, in the presence of β-cyclodextrin in water at 50 °C.
2-氨基-4-烷基-和2-氨基-4-芳基噻唑-5-羧酸盐及其硒唑类似物是通过用N-溴代琥珀酰亚胺对β-酮酯进行α-卤化合成的,然后分别用硫脲或硒脲环化,在 50 °C 的水中存在 β-环糊精。